1/*
2 * Copyright (c) 2003-2005 The Regents of The University of Michigan
3 * Copyright (c) 2007 MIPS Technologies, Inc.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * Authors: Gabe Black
30 *          Korey Sewell
31 *          Jaidev Patwardhan
32 *          Zhengxing Li
33 *          Deyuan Guo
34 */
35
36#include "arch/mips/faults.hh"
37
38#include "arch/mips/pra_constants.hh"
39#include "base/trace.hh"
40#include "cpu/base.hh"
41#include "cpu/thread_context.hh"
42#include "debug/MipsPRA.hh"
43#include "mem/page_table.hh"
44#include "sim/process.hh"
45
46namespace MipsISA
47{
48
49typedef MipsFaultBase::FaultVals FaultVals;
50
51template <> FaultVals MipsFault<SystemCallFault>::vals =
52    { "Syscall", 0x180, ExcCodeSys };
53
54template <> FaultVals MipsFault<ReservedInstructionFault>::vals =
55    { "Reserved Instruction Fault", 0x180, ExcCodeRI };
56
57template <> FaultVals MipsFault<ThreadFault>::vals =
58    { "Thread Fault", 0x180, ExcCodeDummy };
59
60template <> FaultVals MipsFault<IntegerOverflowFault>::vals =
61    { "Integer Overflow Exception", 0x180, ExcCodeOv };
62
63template <> FaultVals MipsFault<TrapFault>::vals =
64    { "Trap", 0x180, ExcCodeTr };
65
66template <> FaultVals MipsFault<BreakpointFault>::vals =
67    { "Breakpoint", 0x180, ExcCodeBp };
68
69template <> FaultVals MipsFault<DspStateDisabledFault>::vals =
70    { "DSP Disabled Fault", 0x180, ExcCodeDummy };
71
72template <> FaultVals MipsFault<MachineCheckFault>::vals =
73    { "Machine Check", 0x180, ExcCodeMCheck };
74
75template <> FaultVals MipsFault<ResetFault>::vals =
76    { "Reset Fault", 0x000, ExcCodeDummy };
77
78template <> FaultVals MipsFault<SoftResetFault>::vals =
79    { "Soft Reset Fault", 0x000, ExcCodeDummy };
80
81template <> FaultVals MipsFault<NonMaskableInterrupt>::vals =
82    { "Non Maskable Interrupt", 0x000, ExcCodeDummy };
83
84template <> FaultVals MipsFault<CoprocessorUnusableFault>::vals =
85    { "Coprocessor Unusable Fault", 0x180, ExcCodeCpU };
86
87template <> FaultVals MipsFault<InterruptFault>::vals =
88    { "Interrupt", 0x000, ExcCodeInt };
89
90template <> FaultVals MipsFault<AddressErrorFault>::vals =
91    { "Address Error", 0x180, ExcCodeDummy };
92
93template <> FaultVals MipsFault<TlbInvalidFault>::vals =
94    { "Invalid TLB Entry Exception", 0x180, ExcCodeDummy };
95
96template <> FaultVals MipsFault<TlbRefillFault>::vals =
97    { "TLB Refill Exception", 0x180, ExcCodeDummy };
98
99template <> MipsFaultBase::FaultVals MipsFault<TlbModifiedFault>::vals =
100    { "TLB Modified Exception", 0x180, ExcCodeMod };
101
102void
103MipsFaultBase::setExceptionState(ThreadContext *tc, uint8_t excCode)
104{
105    // modify SRS Ctl - Save CSS, put ESS into CSS
106    StatusReg status = tc->readMiscReg(MISCREG_STATUS);
107    if (status.exl != 1 && status.bev != 1) {
108        // SRS Ctl is modified only if Status_EXL and Status_BEV are not set
109        SRSCtlReg srsCtl = tc->readMiscReg(MISCREG_SRSCTL);
110        srsCtl.pss = srsCtl.css;
111        srsCtl.css = srsCtl.ess;
112        tc->setMiscRegNoEffect(MISCREG_SRSCTL, srsCtl);
113    }
114
115    // set EXL bit (don't care if it is already set!)
116    status.exl = 1;
117    tc->setMiscRegNoEffect(MISCREG_STATUS, status);
118
119    // write EPC
120    PCState pc = tc->pcState();
121    DPRINTF(MipsPRA, "PC: %s\n", pc);
122    bool delay_slot = pc.pc() + sizeof(MachInst) != pc.npc();
123    tc->setMiscRegNoEffect(MISCREG_EPC,
124            pc.pc() - (delay_slot ? sizeof(MachInst) : 0));
125
126    // Set Cause_EXCCODE field
127    CauseReg cause = tc->readMiscReg(MISCREG_CAUSE);
128    cause.excCode = excCode;
129    cause.bd = delay_slot ? 1 : 0;
130    cause.ce = 0;
131    tc->setMiscRegNoEffect(MISCREG_CAUSE, cause);
132}
133
134void
135MipsFaultBase::invoke(ThreadContext *tc, const StaticInstPtr &inst)
136{
137    if (FullSystem) {
138        DPRINTF(MipsPRA, "Fault %s encountered.\n", name());
139        setExceptionState(tc, code());
140        tc->pcState(vect(tc));
141    } else {
142        panic("Fault %s encountered.\n", name());
143    }
144}
145
146void
147ResetFault::invoke(ThreadContext *tc, const StaticInstPtr &inst)
148{
149    if (FullSystem) {
150        DPRINTF(MipsPRA, "%s encountered.\n", name());
151        /* All reset activity must be invoked from here */
152        Addr handler = vect(tc);
153        tc->pcState(handler);
154        DPRINTF(MipsPRA, "ResetFault::invoke : PC set to %x", handler);
155    }
156
157    // Set Coprocessor 1 (Floating Point) To Usable
158    StatusReg status = tc->readMiscRegNoEffect(MISCREG_STATUS);
159    status.cu.cu1 = 1;
160    tc->setMiscReg(MISCREG_STATUS, status);
161}
162
163void
164SoftResetFault::invoke(ThreadContext *tc, const StaticInstPtr &inst)
165{
166    panic("Soft reset not implemented.\n");
167}
168
169void
170NonMaskableInterrupt::invoke(ThreadContext *tc, const StaticInstPtr &inst)
171{
172    panic("Non maskable interrupt not implemented.\n");
173}
174
175} // namespace MipsISA
176
177